feature: NEWS2 Composite Scoring Engine

VigilCareClinicalAPI/Observability/Metrics/ClinicalMetrics.cs

@@ -24,6 +24,11 @@ public sealed class ClinicalMetrics
         "sirs_detections_total",
         "Total SEPSIS_WARNING alerts generated by the sepsis detection engine.");
 
+    public readonly Counter News2ScoresTotal = Metrics.CreateCounter(
+        "news2_scores_total",
+        "Total NEWS2 scores computed, labeled by risk level.",
+        labelNames: new[] { "risk_level" });
+
     // Incremented by EscalationWorkerService when it processes a message from
     // alerts.escalation.queue. A rising escalations_total is the strongest operational
     // signal that critical alerts are not being acknowledged by the attending physician.
@@ -44,6 +49,14 @@ public sealed class ClinicalMetrics
             Buckets = new[] { 0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1.0 }
         });
 
+    public readonly Histogram News2ScoringDuration = Metrics.CreateHistogram(
+        "news2_scoring_duration_seconds",
+        "Time to compute a NEWS2 score from Redis state.",
+        new HistogramConfiguration
+        {
+            Buckets = new[] { 0.001, 0.005, 0.01, 0.025, 0.05, 0.1 }
+        });
+
     // --- Gauges (set by background collectors, not incremented inline) ---
 
     // The most clinically significant panel. A non-zero value means a patient's